...
The trick is to render both controls and then turn one of the side’s controls off. This can be done by setting the e.Cancel property to true - this way the control instance will be removed from the report.
However, paging is only know known after every control has been laid out and page size has been taken into account (and grouping rules where data should be shown), so you will need to use the PrintOnPage event as controls wont know which page index its on until after PrintOnPage is done. The event will include the pageindex in the PrintOnPageEvent sent to the script method. Default the PageIndex is 0 based so first page is pageindex = 0 unless overridden.
...